Preparing the flat roof

Jesse is hard at work, putting final touches on the plywood decking

 Although the main roof of the house is finished, the upstairs deck, aka "sleeping porch" of the house, requires a flat roof underneath the deck boards. Flat roofs aren't truly flat, they are sloped very slightly to ensure drainage. You can read about how we created that slope in an earlier post, which is most easily found by clicking here. Flat roofs are also very tricky to install correctly, and can cause a lot of expensive damage if they fail, especially when they are installed over a living space. We've found a roofing company that is up for the job, but there's been plenty of work to do getting everything ready for them.

Our friend Richard has come out a few Saturdays to help with the last of the exterior framing

For one thing, a few walls hadn't yet been framed. These walls aren't structural, but they create the boundary between the interior and the exterior, and they have to be in place before the roofing material can be installed. That's because the roofing material needs to come up the sides of the wall about 4 or 5 inches all the way around. Several of these walls will be covered on both sides by Polygal, a translucent plastic panel, but the bottoms of the wall need to have plywood to which the roofing material can adhere.

Jesse measuring to fit plywood around the base of a column

The roofing material will be a product called TPO. It gets installed over a thin layer of rigid insulation which cushions and protects it from damage from below, and also helps the roofing material not be affected by any expansion or contraction in the framing. Around the perimeter of the roof, however, I put a band of 1/2" plywood to give the roofers a more secure means of attaching the first layer of TPO. The only place I didn't put the 1/2" ply is at the scuppers, where I used some 1/8" ply so there will be no danger of the layers of material building up and preventing water from flowing outwards.

Photo of scupper rough openning, showing 1/2" plywood perimeter and 1/8" plywood in the scupper itself.